Molybdenum disulfide (MoS₂) is considered as one of the most effective materials which can supersede the high cost and scarcity of metal platinum (Pt) for the hydrogen evolution reaction (HER). One road block lying in access to high catalytic performance of MoS₂ emanates from the inert basal plane. To enable inert basal plane of flexible MoS₂, we demonstrate an effective synthesis strategy via the progressive transformation of MoS₂ to MoS_2-xO_x with O atomically dispersed under actual photo-catalytic hydrogen evolution condition. The rate of hydrogen production of new reconstructed MoS_2-xO_x nanosheets is improved to be much higher than that of the initial MoS₂. Our theoretical calculation results indicate that the appropriate O substitution and strain could modulate the surface electronic state and optimize the Gibbs free energy (ΔG_H) of MoS₂, thus dramatically accelerating the catalytic efficiency. This work showcases a promising route to achieve tunable photochemical reconstruction by optimizing the electronic structure for low-cost and robust MoS₂-based HER catalysts.

二硫化钼（MoS ₂）被认为是最有效的材料之一，可以取代用于氢气析出反应（HER）的金属铂（Pt）的高成本和稀缺性。一种获得MoS _2的高催化性能的障碍来自惰性基础平面。为了使柔性MoS _2的惰性基面成为可能，我们通过在实际的光催化制氢条件下，通过将OS原子分散为MoS ₂逐步转变为MoS _2-x O _x，证明了一种有效的合成策略。新型MoS _2-x O _x的制氢速率纳米片被改进为比初始MoS ₂高得多。我们的理论计算结果表明，适当的O-取代和应变可以调节表面的电子状态，并且优化的吉布斯自由能（ΔG _ħ的MOS）₂，从而大大加快催化效率。这项工作展示了通过优化低成本和坚固的基于MoS ₂的HER催化剂的电子结构来实现可调谐光化学重建的有前途的途径。